Ergonis Software's PopChar Win is similar to the Windows Character Map, but more convenient. It waits in the system tray until you need a special character. Just click its icon to get a list of characters nicely organized by Unicode type. When possible, PCW detects and uses the current font in the underlying application. Click a character to insert it  you can configure PCW to hide after insertion or wait for more selections. For convenience it tracks the characters and fonts you've most recently used.